As sure as a Memorial Day parade, gasoline prices have steadily marched higher this week, creating real pain at the pumps across the Great Lakes.

The average price in Greater Cleveland on Friday is $3.86 a gallon, says GasBuddy, 22 cents above the national average of $3.64, and 8 cents higher than last year's average price on Memorial Day.

It's the same story throughout the region, with Chicago at the peak of $4.02 a gallon, for a special clean blend to meet federal air standards.

Blame the usual suspects:

-- U.S. Energy Information Administration reports in the last two weeks showing that implied demand is running above 9 million barrels a day;

-- Crude oil prices at $104 and rising;

-- The annual AAA telephone survey predicting more than 36 million families -- up 1.5 percent from last year -- will drive 50 miles during the long weekend.

"The Midwest is unique. Prices go up because the demand curve is rising, or they think it is rising," Tom Kloza, chief oil analyst, GasBuddy, OPIS.

But that doesn't explain the much higher average prices here.

"Wholesale prices peaked around April 20, and have been drifting and wobbling since. Here (Midwest) they have been wobbling higher," said Tom Kloza, chief oil analyst for GasBuddy.

Back then, Greater Cleveland dealers said they were paying about $3.53 to $3.55 a gallon -- including freight charges and state and local taxes.   On Friday, they were paying $3.70 to $3.80, including all charges.

Kloza said he knew of no major refinery or pipeline disruptions in the region.

"The Midwest is unique. Prices go up because the demand curve is rising, or they think it is rising," he said. "Our surveys show demand is not as high as believed, and we are not going to be using 9 million barrels of gasoline a day."

Bottom line? Whether it's called shrewd marketing, a response to perceived demand increases, or greed, the reasons for the high prices will be short-lived.

"Gasoline should be very well supplied, particularly in the Midwest," said Kloza. "We will look back at these prices on July 4th and say that they were higher."